Hello, in this article I want to show you the most common problems with crowns of watches and their removal.
CROWN UNSCREWS.
If the crown unscrews in normal use, it may be caused by the
threads being stripped on the stem or crown, stem rusted on the inside
mechanism, the clutch or winding pinion binding, or the cannon pinion
too tight or binding in the dial train or setting wheel. To determine
the cause, remove movement from the case and remove the hands
and dial. Examine threads on stem and crown with an eye loupe.
To determine the other causes, disassemble the winding and setting
mechanism, and inspect for broken or rusted parts.
To correct any of these conditions, replace defective parts.
STEM PULLS OUT.
If the stem pulls out, check for loose setting lever screw or
stripped threads. Check the setting lever for broken parts, wear, or
stripped threads. Check stem for size, or shoulder for being too small.
Check recesses in barrel bridge for wear and for loose or bent bridge.
To determine this condition, remove movement from case and remove
hands and dial. If the error cannot be observed, disassemble the
winding mechanism.
Worn or broken parts of the winding mechanism must be re-
placed. If recesses in barrel bridge or pillar plate are worn, a new
stem will have to be made to fit, since new bridges or pillar plates are
not available as spare parts.
WATCH CAN BE WOUND BUT NOT SET.
This condition may be caused by an improperly engaged clutch;
broken clutch teeth; broken or worn setting lever; minute wheel slip-
ping out of mesh with setting wheel or cannon pinion due to broken,
worn, or loose stud of either wheel; teeth sheared off hour or minute
wheel; cannon pinion broken or loose, causing it to shift out of mesh
with minute wheel; or by a broken clamp assembly. To determine
the cause, remove movement from case and remove hands and dial.
Engage the setting mechanism and rotate it to check for above condi-
tions.
Any parts that are worn or broken in the setting mechanism
must be replaced. If the minute wheel, setting wheel, and cannon
pinion are not meshed, straighten the studs until proper mesh is
obtained. If the cannon pinion is too loose, it may be tightened; or
if it is too tight, it may be broached out to fit properly.
WATCH WILL SET BUT NOT WIND.
This may be caused by a broken mainspring, broken clutch lever
spring, broken click or click spring, sheared or stripped teeth on the ratchet wheel, crown wheel, winding pinion, cannon pinion, loose barrel
cover, hook on barrel worn or barrel arbor broken, or stripped screws
which cause parts to become loose and out of adjustment. To deter-
mine the cause, remove movement from case, wind the watch and check
the click and click spring, and crown and ratchet wheels, and check the
screws retaining these parts. Remove hands and dial, wind the watch,
and note operation of the winding mechanism. Check the power assem-
bly by removing the ratchet wheel and lifting the barrel assembly
out; check the barrel cap to see that it fits snugly into its recess. Re-
move barrel cap and check the mainspring to see that it is not broken
and is properly hooked on the barrel at the outer end and on the arbor
at the inner end.
Replace worn or broken parts; replace screws which have worn
or stripped threads.
WATCH WILL NOT WIND OR SET.
The cause will be a broken clutch lever, clutch lever spring, or
the stem broken below the bottom shoulder. To determine this, remove
movement from case and remove hands and dial. Check the clutch
lever, clutch lever spring, and the stem below the bottom shoulder.
To correct this condition, replace broken, worn, or rusty parts.
WATCH IS HARD TO SET.
This cause may be due to rusty parts, cannon pinion being too
tight, minute wheel stud bent, a bent tooth on any of the wheels in the
setting mechanism, or a weak clutch lever spring. To determine the
cause, remove movement from case and remove hands and dial. With
the clutch in setting position, rotate dial train and check for any of
the above conditions.
To correct condition, replace broken, worn, or rusty parts.
Straighten the minute stud, if bent; if stud is loose, replace it.
WATCH HARD TO WIND.
This may be due to bent stem, movement not cased properly,
crown too small or knurling worn off, or rusty parts. To determine
cause, inspect crown for size and condition. Rotate crown and, by
feeling, note whether or not stem is binding at any point. Check to
see that the movement is properly seated in the rebate of the case.
Remove movement from case. Remove hands and dial to check wind-
ing mechanism and for rusty parts.
To correct condition, replace a small or worn crown; replace a
bent stem. Reseat movement if improperly seated in case. Replace
all rusty parts.
STEM SLIPPING IN SETTING POSITION.
The cause may be improper depthing of the sleeve in pendant,
sleeve worn, weak, or broken, stem shoulder worn, or setting spring too
strong. To determine the cause, pull crown out to setting position and
rotate it to see if it slips. Remove crown, sleeve, and stem assembly
from the pendant and check to see if sleeve is worn, weak, or broken.
Check stem shoulder for wear. Remove movement from case; remove
hands and dial to check setting spring.
If stem slips in setting position, adjust the sleeve in or out to
correct the trouble. If the sleeve is worn, weak, or broken, replace it.
If stem shoulder is worn, replace it. If the setting spring is too strong,
replace with a weaker spring.
WATCH DOES NOT WIND TIGHT.
This indicates that the mainspring slips off arbor hook or barrel
hook. To determine the cause, remove movement from case and re-
move ratchet wheel screw and ratchet wheel. Remove barrel bridge.
Remove barrel assembly and snap out barrel cap. Inspect mainspring
to see that it is hooked at both ends.
